I. Introduction
Mechanical resonances in induction motor drives have long been studied due to their detrimental effects such as disturbing noise [1], excessive vibrations [2], and even damage of mechanical and electrical parts [3]. The literature covers both line-fed fixed-frequency drives (FFDs) [2] and inverter-fed variable-frequency drives (VFDs) [4]. Motor resonances can be classified based on the resonant part/assembly as [5]:
Rotordynamic (shaft lateral and torsional vibrations)
(frame, stator core, foundations, supports, etc.)
(fans, bearings, teeth, terminal boxes, etc.).